Coking retort oven



Sept. 13, 1938. H. DREHscHMlDT 2,129,658

coKING RETORT OVEN Filed Aug. 8, 1955 2 Sheets-Sheet l Iig-1 Sept. 13, 1938. H. DREHscHMlb-r COKING RETORT OVEN Filed Aug. 8, 1935 2 Sheets-Sheet 2 A4 war-y.

charge during the middle temperature carbonizahigh temperature coking, especially if the coking ovens the temperature of the heating walls is as a middle temperature coking, which have lgreat 'Patented Sept. 13, i938 l COKING BETOBT OVEN Heinrichlrehschmidt, Esscneon-the-Ruhr, Germany, assigner, by. mesne assignments, to Koppers Company, Pittsburgh, Pa., a corporation of Delaware l application august s, 1935, serial No. 35,256 I y In Germany December 12, 1933 Claims. (Gl. 2oz-139) This invention relates to the distillation (colrtion of the hydrocarbons resulting therefrom, ing) of bituminous fuels in ovens of the known which can lead to the separation of graphite,' is type illustrated on the drawings for the produccounteracted according to the invention through tion of gas' and coke, and has for its object to the fact that the gas collecting crown-space of the improve the quantity and type of lay-products coking chamber of the oven or the cracking chamarising from the distillation of such fuels in such ber, into which the distillation gases pass from lthe coiring zone of the chamber, is maintained at a temperature lower than that oi the heating walls of the coking chamber.

It is obvious from the alcovel that the fundamental rule ofthe invention maires possible a further step in the development of a carbonizatlon oven, in which it is possible to obtain by suitably adjusting the heating of the coking zone of the chamber and the gas collecting space l of the chamber receivingthe distillation gases, an extensive alteration in the quality and quantity of all products obtained from the coke ovens, i. e. coke as well as by-proclucts, varying in accordance with the conditions and possibilities obtaining. It is obvious what importance the introduction of such a coke oven will haveto the coklng industry with the present day economic conditions all over the world.

The fundamental idea of the invention is preferably realized by subjecting the gaseous and vaporous distillation products, after their disn charge from the fuel charge of the coking oven, but before cooling and condensing, to a heat treatment in a cracking chamber connected with the colsing chamber, and whose wall temperature can be adjusted higher orlower independent of that of the carbonization chamben preferably at temperatures between 600 and 800 C.

v The coking oven serving to carry out the process according to the invention exhibits the fundamental peculiarity that the walls of the gas collecting crown-space of the chamber, i. e. of the chamber zone above the zone .for Athe coking charge, even after shrinkage of the same during coking, are not traversed by the main heating passages serving to heat the cokingzone of the chamber and the gas collecting chamber may 'oe connected to the cracking zone' of an adjacent chamber by a conducting pipe and which latter zone is heated or cooled by its wall passages, which can be regulatedlndependently of heating wall passages of the coklng zone of itschamber'oven, according to the temperature which arises in the 'ioven during a definite state of operation.

I In horizontal chamber coke ovens this basis arrangement is preferably andmost simply arranged somewhat as follows:

The cooking chamber of the horizontal chambers is heated by vertical heating passages which Unirse STATE The invention consists in maintaining the hot distillation gases, arising from the distillation of bituminous fuels, for a definite time at such a temperature, or heating or cooling-themto such a temperature, before cooling or condensation that the hydrocarbons in the gases are converted to valuable products, and independently o'f the temperature which the gases acquired in the coli-l ing zone of the coking chamber.

The technical advantage obtained from the application 'of the foregoing briefly described main technical rule, is best illustrated in the so-called middle temperature coking of bituminous fuels, i. mocking in lwhich the coking charge is brought to a maximum temperature of preferably 60o-700 C( With such low coking temperatures a tar is obtained in the lay-products, whose properties deviate considerably from those of the vtar usually obtained in coking. Ii' the vaporous and gaseous products discharging from the coking tion are subsequently heated in a cracking chamber, arranged for example, above the coking chamber,to temperatures of about 650J750 C., the hydrocarbons change to compounds such as are normally found in high temperature coking. In this way byproducts are obtained during economic advantages with respect to the quality of the coke produced, and are of high value.

Similar conditions sometimes exist in the known oven is operated with a considerably longer work@- ing period. In this case the-temperature in'the gas collecting chamber decreases to a large extent so that there are no longer any changes in the hydrocarbons in which event the high yield of valuable by-products is reduced during the high temperature carbonizatlon.

Onvthe other hand the use of.the fundamental technical rule of the present invention, even with high temperature coking,iwith a normal or short--` cned operative coking time results in considerable technical advantages. In the modern high-duty rule very high and on this account the 4gas collectingV chamber is sometimes heated excessively. The too extensive and unfavourable decomposiz,129,6ss l are connected in 'pairs according to the known circulation principle. The upper connecting opening between the two co-operating heating passages of each pair of heating passages is arranged at such a height below the top level for coked charges that even after the shrinkage of the coal charge during the coking process there is no excess heating of the gas collecting space chamber by the heating es for the coking zone of the chamber. The upper connecting opening of the pair of heating passages is then Y in such a position that the cated lump of coke,

' advantage.

with simultaneous pressure on its upper edge, becomes a thin dark layer. In this position of the upper connecting opening of the heating es the gaseous distillation products zare protected from too extensive heating and dispersion.

In order to heat the gas collecting crown-space of the chamber serving as a cracking chamber, or ,a special cracking chamber connected with the gas collecting chamber, vertical es controlled by valves.` are provided above the vertical passages of the heating walls and are connectedand are closed from. the outside by means of a removable cover, provided ii necessary with adjustable openings.

In horizontal chamber coke ovens which are operated with a poured-in chamber load the gas collecting crown-space of' the colzing chamber is preferably combined with the cracking chamber. llt is however also possible to provide a special cover passage, above the special gas collecting chamber, to be constructed below, which would preierably be connected by means ci calibrated openings tothe' gas cohecting chamber on. the one hand and with the ascension pipe 'on the other hand, in such a way that the `distillation gases escape into the ascension pipe by means of the cover passage acting as a cracmng chamber. The cover passage in these forms oi construction must obviously lie in reach of the heat= ing passages for the crashing chamber.

The arrangement ci the cracking chamber in the form of a special cover L: f e has in addition the advantage that by means of a suitable adjustment of the valve controlling the openings in the gas collecting chamber the distillation gases can be drawnV off rst of all through the gas collecting space in its entire length and then through the cover w over its'whole extent. 0n this account, the time during which the distillation gases are submitted to the heat treatment is, under the circinnstances. increased with En auch horizontal chamber coke ovens which are supplied with preformed charges of coal pressed into the shape of a cake fitting the cok- -ing sone of the chamber oven prior to the charge being introduced into the oven, a special cover passage which can be connected with the real gas collecting ber. of a special low con- *onthelineVv-vofligmea struction, is preferably provided regularly as a cracking chamber.

It has in addition been found that the height to which the chambers are adapted for being charged .with coal, or in other vvorcls.y the now of heat from the heatingwall es of the carbonization zone of the chamber to the surface of `the coked charge, which accordingly limits the gas collecting space of--the chamber, determinesthe temperature of the gas collecting space of the chamber as well as the heating of the gas collecting zone walls A further object of the present invention is to make adjustable the flow of heat from the heating wall es of the coking chamber over the coal charge to the gas collecting chamber.' This obiect is fundamentally obtained according to the invention by means of the. fact that the coal charge is smoothed out at such a height that the desired flow of heat takes place from the heating wall es of the oo king chamber to the surface of the coal charge. It is clear that with aA different height of the coal layer above the heat. ing wall passages it is also possible to effect an increase or decrease of the fail of temperature between the upper end of-the heating wall passages (in the so-called twin heating f 1 Y. the said upper return point also) and the uppe side of the coal charge terminating below the gas collecting space'of the chamber.

The practical operation of the process according to theinvention is preferably carried out in the known horizontal chamber coke ovens for the production of gas and coke in such a way that the levelling bars for levelling the coal charge can be operated vat different heights according to the kind of coal charge and that the levelling opening providedgin the colxing chamber door is ci auch a size that the coal charge can at any time be levelled at the desired height. As a variation in height of coal charge is contemplated, the levelling bar opening lies more or less underby their heath the top level for some coal charges, means are provided, according to the invention, for ect-1 ample, removable supporting shields., -in orderto support the coal in the chamber with high iev l ling by the levelling bars andto prevent the coal which the distillation gases can ow out from on chamber into the next. This arrangement that the distillation gases are maintained Ffor a longer time at a dennite temperature. which is a great advantage for carrying out deilnite changes in the hydrocarbons in certain cases.

Figure 1 of the drawings shows a vertical longitudinal section through a horizontal chamber coke oven constructed according to the invention and adapted for chute-operation.

FigureBshowsaverticalsectionontheline II-II of Fig. l.'

Figure 3 showsahorinontal section on thelinel III-LUI of Fig. i.

Figure 4 shows a vertical longitudinal section through a horizontal chamber coke oven supplied with preformed pressed coal charges.

j Figure 5 merely shows a vertical cross section In the coke oven illustrated in Fig. 1, horizontalv coking chambers I alternate in the known manner with walls in which vertical heating passages 2, 3 are provided. A heating passage 2 and a heating passage 3 are connected with each other in pairs at the upper ends through the opening 4 and at the lower end through the opening 5. In this way the known circulating heat passage is formed in the wall. Gas and air for combustion are supplied to the lower end through passages 6, whichx are connected in the known manner with the regenerators (not shown).

As can be seen from the drawings the upper connecting opening 4 of the heating passages lies at such a height that even after the chamber load has settled down, during or towards the end of the coking' the gas collecting chamber space 1 does not lie within reachof the heating passages 2. In Fig. 2, the charge of coal is indicated in the left chamber 8 shortly after illling with coal and through closable cover openings I3, by means of positioning bars. The passages I and II are connected to each other by cross passages I4,

forming hair pin heating passages.

The gas collecting chamber space 1, which also serves as a cracking chamber Ain the oven illustrated, lies in the plane of the upper passage system formed bythe passages III, II and I4. It is obvious that by adjusting the valve suitably a sufficient quantity of heating gas can be supplied from the heatingpassages 2, 3, through the upper passage system to heat the walls of the cracking chamber space 'I as required. If it is a question of an oven for the middle temperature coking of fuels, in which low coking temperatures and therefore, as a rule, comparatively low heatingpassage temperatures are used, it is advantageous, under the circumstances, tomake the dividing wall between the Acracking chamber space and the upper heating passage system thinner than the dividing wall between the coking zone of the chamber and the vertical circulatory heating passages 2, 3. In this way the cracking chamber space, in exceptional cases, is well heated to temperatures which lie above that of the coking zone of the chamberwall.

In addition, according tothe invention a layer of brickwork` I separating the cross passage I4 from the heating passages 2, 3, is arranged at such a height that it is impossible for too much heat to iiow from the heating passages 2, 3, into the part of the brickwork forming the gas collecting chamber space.l

Cooling shafts I6, which also serve as lling` openings are provided in the cover in the oven according to Fig. l in order to cool the gas collecting chamber space vor cracking chamber, and are cut off from the gas collecting chamber space through a comparatively thin walled covering piece I1 and which can be closed on top by means of a cover 11a. By removing the cover I1 it is possible to lower the temperature of the entire cracking chamber space or definite parts of the lsame to the desired temperature.

An opening for the connection to the ascension pipe I8 is provided at one end of the oven chambers in the usual` manner.

The chambers I, Ia which receive the coal y charge to be coked is closed on both faces, during the coking process, by means of doors I9, lila.

In order to regulate the temperature of the gas collecting chamber space, the charge of coal is levelled out at different levels as indicated by the dotted lines 8a. For this purpose a longitudinal opening 20 is provided in the chamber door I9a, and can be closed by means of a cover 2|. The opening permits of the introduction of .the levelling bar 22 whose roller support rests on elbow levers 24 which can be rotated by means of a bar 25 and driving gear 26. As can be seen from Fig. l it is possible, by means of suitable adjustment of the elbow lever 24, to allow the levelling bar to run at diiferent levels with regard to the oven chamber.

Projections, or pintles, or cut out portions or pintle bearings, 21 in which a supporting shield 28 may be interchangeably xed are provided in the levelling vbar opening 20. These out out portions 21 are at various levels, so that it is possible to support the upper border of the coal at different levels in comparison to the downwardly directedv levelling bar openings.

An opening 29 to which4 is joined a U-tube 30 is provided in the cover of the oven at the end lying opposite the ascensionl tube connection. As.

can be seen from Fig. 2 the U-tube is constructed ,in such a manner that the openings 29 of two neighbouring chambers are connected with each other. The U-tube 30 is preferably surrounded with a heat insulating material. In addition it is constructed with a cut-off device, preferably closed, whilst the ascension pipe 18a of the adja cent oven chamber la remains opened and in addition the U-tube 30 is opened between both coking chambers. The distillation gases then pass out of the chamber I through the U-tube 30.

into the gas collecting chamberof the oven chamber Ia and from thence lthrough the ascension pipe Isa.

It is generally preferable to supply and discharge 'the chambers in such a way that the operative condition of both chambers connected to each other always differs by about half the operative coking period. In this way it is always possible4 to subject the distillation gases to the same heat treatment, whilst for example' after filling coal in the chamber I (see Fig. 3) the distillation gases low'rst of all in the direction of the arrow 32a and after filling coal in the chamber la the gases go the opposite way in the direction of the arrow 32, according. to a corresponding alteration of the cut-off device of the ascension pipe and of the U-tube 30.

The coke oven illustrated in Figs: 4 and 5 is adapted to be supplied lwith preformed coalcharge cakes. The heating system ofthe coking chamber and the cracking chamber is fundamentally the same as in the oven according to Figs. 1 and 2.

The gas collecting chamber space 33 is constructed lowerl In the oven according to Figs. 4

-\ and 5. An upper cracking chamber 34 is arranged in the cover of the oven, within the gas collecting chamber space, and is connected with the lower gas collecting chamber space through the calibrated openings 35. 'I'he openings 35 lie underneath the cover openings 36 and can if desired be controlled by valve plates 31.

The ascension pipe 36 is connected to the upper cracking chamber 3l at the middle of the coking chamber, and is lined inside with re brick and as it were forms an extension of the upper cracking chamber 34.

Cooling shafts 39 which are arranged in the cover of the oven also serve to cool the upper cracking chamber.

'Ihe foregoing has described the application of the -invention for horizontal chamber coke ovens -with vertical circulatory heating passages. The

invention is however not limited to such ovens but can be used with equal advantage in all coking ovens.

Finally the width of the coking chambers b etween the heating walls may be briefly discussed. In-order to obtain a high yield of by-p'roducts and to maintain a relatively low coking temperature necessary for the same, it is advantageous to select coking chambersnot broader than about 350 mm. This width of chamber is also favourable insofar as it enables middle temperature coking to be carried out economically without this width of chamber unfavourably influencing with regard to the particle size, the high temperature coke, produced if necessary in the same oven.

I.wish it to be understood that the invention is disclosed in the foregoing merely by way of example and that it isof course not limited to this example. On the contrary, I expressly reserve the right to carry into effect my invention in any desired manner coming within the scope of the appended claims.

I claim:

l. In a coking retort oven, in combination: a series of alternate horizontal coking chambers and heating walls therefor arranged side-byside in a row, each of said coking chambers being adapted for being charged full of coal save for a gas space in the crown-space thereof left for collecting gas above the coal charge therein and also being adapted for having a top level for coked charges therein; each of said heating walls having main combustion flues comprising individual to the respective main hairpin flues, alongside the aforesaid gas collecting spaces of the adjoining coking chambers, the main heating `flues being provided with means at their upper parts for off-flow therefrom at their upper parts of waste gas so as to by-pass the separately regulable heating flues, and the separately regulable heating ilues being communicably connected by regulable ports having regulating means'therefor with the main heating flues below the separately regulable heating ues for regulable flow of some of the waste heating gases 'from the main heating flues to the separately regulable heating flues.

2. In a coking retort oven, in combination: a series of alternate horizontal coking chambers and heating walls therefor arranged side-by-side in a row, each of said coking chambers being adapted for being charged full of coal save for a gas space in the crown-space thereof left for collecting gas above the coal vcharge therein; each of said heating walls having main 'combustion flues extending nearly up to but terminating below the aforesaid top level for coked' charges and having separately regulable heating `flues alongside the aforesaid gas collecting spaces of the Vadjoining coking chambers, the main heating flues being provided with means at their upper parts for off-flow therefrom at their uppe 'parts of waste gas so as to by-pass the separate y regl ulable heating flues, and the separately regulable heating ilues being communicably connected by regulable ports having regulating means therefor with the main heating ues below the separately regulable heating flues for regulable flow of some of the waste heating gases from the main heating flues to the separately regulable heating flues and in which the main heatingr passages are vertical combustion flues which terminate at their' upper parts sufficiently below the top level for coked charges so that the top layer of the coked charge next to the gas collecting crown-space may be less highly heated than the portion of the coking charge immediatelyv below its tcp surface whereby at the end of the coking operation the top of the coking charge may be heated to la temperature to form but a thin dark layer rather than an incandescent layer which would crack vgases owing thereover through the gas collecting crown-space.

3. In a coking retort oven, in combination: a series of alternate horizontal coking chambers and heating walls therefor airanged side-by-side in a row, each of Isaid coking chambers being adapted for being charged full of coal save for a gas space in the crown-space thereof left for collecting gas above the coal charge therein/ and also being adapted for having a top level for coked charges therein; each o f said heating walls having main combustion iiues extending nearly up to but terminating below the aforesaid top level for coked charges and having separately regulable heating flues alongside the aforesaid gas collecting spaces of the adjoining coking chambers and communicably connectedby regulable ports having regulating means therefor with the 'main heating flues below the separately regulable heating iiues for regulable ilow of heating gases from the main heating flues to the separately regulable heating iiues and in which the main heatingl passages are constituted of vertical hairpin flues and in which the separately regulable heating passages and their ports are constituted as supplemental but smaller hairpin flues individual to the main hairpin fluesV for flow in series of a portion of the heating gas from one of the limbs of the main hairpin flues into one of the smaller hairpin flue limbs and thence from the other limb of the smaller hairpin flue limbs to the other of the limbs of the main hairpin fiue.

4. In a coking retort oven, in combination: a series of alternate horizontal `coking chambers and heating walls therefor arranged side-by-side in a row, each of said coking chambers being adapted for being charged full of coal save for a gas space 'in the crown-space thereof left for collecting gas above the coal charge therein; .each of said heating walls having main combustion flues extending nearly up to but terminating below the aforesaid top level for coked charges and having separately regulable heating flues alongside the 4aforesaid gas collecting spaces of the adjoining coking chambers, the main heating flues being provided with means at their upper parts for off-flow therefrom at their upper parts of Waste gas so as to by-pass the separately regulable heating flues, and'the separately regulable heating flues-being communicably connected by regulable portshaving regulating means therefoi` with the main heating flues below the separately regulable heating flues for regulable flow of some ofthe waste heating gases from the main heating ilu'escto the separately regulable heating flues and in which anY ascension pipe is provided at one end'of each colringchamber for communication -with its gas collecting space and a port. is provided at the opposite end of each of ,said

coking chambers in communication with the gas collecting space thereof, and means are provided for communicably connecting the latter mentioned port of each of said coking chambers with the similar port of another of said chambers forcollecting gas above the coal'charge therein; each of said heating walls having main combustion flues extending nearly up to but terminating below the aforesaid top level 'for coked charges and having separately regulable heating flues alongside the aforesaid gas collecting spaces of the adjoining coking chambers, the main heating flues being provided with means at their upper parts for off-flow therefrom at their upper parts of Waste gas so as to by-pass the separately regulable heating fiues, and the separately regulable heating flues being communicably connected by regulable ports' having regulating means therefor with the main heating flues below the separately regulable heating flues for regulable flow of some of the waste heating gases from the main heating ues to the separately regulable heating flues and in which vertical cooling shafts are provided in the top of each cokingchamber for cooling gas flowing through .the gas collecting `gas ow into the surrounding atmosphere by a comparatively thin cover plate and having at the upper parts a removable cover at the -opper extremity of the shaft and exposed to the atmosphere, the thin coverplate being disposed intermediate the upper and lowerfextremities of the shaft and spaced from the removable cover at the top and the lower termin-us ofthe shaft at the bottom so as to provide a lower heat accumulating pocket chamber in the shaft below the thin cover and an upper radiant-heat retarding-chamber in the shaft above the thin cover and below the removable cover for controlling the cooling of theV crown-space gases, the removable cover being removable for exposing the thin cover plate to direct cooling action of the surrounding atmosphere.

6. In acoking retort oven, in combination: a'

series of alternateA horizontal coking chambers and heating walls therefor arranged side-by-sicle in a row, each of said coking chambers being adapted for being charged full of coal save for a gas space in the crown-space thereof left for collecting gas above the coal charge therein; each of said heating walls having main combustion flues extending nearly up to but terminating below the aforesaid top level for coked charges and having separately regulable-heating flues alongside the 'aforesaid` gas collecting spaces of the adjoining coking chambers;`- the main heating .flues being provided with means at their upper parts fory off-flow therefrom at their upper parts of waste gas so as to by-pass'the separately'regulable heating flues, and the separately 'regulable heating flues being communicably connected byfy regulable ports having regulating means there# for with the main heating flues below the separately regulable heating flues for regulable flow of some of the waste heating gases from the main heating flues to the separately regulable heating flues and in which vertical cooling shafts are provided in the top of each coking chamber for .cooling gas owing through the gas collecting space of e'ach coking chamber, said shafts communicating at their lower partsy with the gas collecting space of the coking chamber to provide a relatively cool zone for radiation of heat to the atmosphere from gas flowing through 'the gas collecting space, said shafts being cut-ofi from gas flow into' the surrounding atmosphere by a comparatively thin coverplate and having at the upper parts'a removable cover at the upper extremity of the shaft and exposed to the atmosphere, the thin coverplate being disposed intermediate the upper and lower extremities of the shaft and Ispaced fromthe removable cover at the thin cover and an upper radiant-heat retardingchamber in the shaft .above the thin cover and below the removable vcover for controlling the cooling of the crown-space gases, the removable cover being providedv with adjustable ports for influx of air into contact with the thin cover plate from the surrounding atmosphere to'cool the same either through the covering plate o r upon removal of the same.

7. In aV coking retort oven, in combination: a series of alternate horizontal coking chambers and heating walls therefor arranged side-by-side in a row, each of said coking chambers being adapted for being charged full of coal savefor a gas space in thecrown-space thereof left 4for collecting gas above the coal charge therein; each of said heating Walls having main combustion flues extending nearly up to butterminating below the aforesaid top level for coked charges and having separately` regulable heating ilues alongside the aforesaid gas collecting spaces of the adjoining coking chambers the main heating flues being provided with means v'at their upper parts for off-flow therefrom at their upper parts of waste gas so as to by-pass the separately regulable vheating flues, and the separately regulable heating flues being communicably'connected by regulable ports having regulating means therefor with trie main heating flues below the separately regulable heating flues for reg-ulable ow of some of the waste heating gases from the main heating flues to the separately regulable heatingA `each of said coking chambers in communication 75 with the lower gas collecting space and in the same plane as the separately regulable heating -passages in the adjoining heating Walls.

y8. In a cokingretort oven, in combination: 'a series of alternate horizontal coking chambers and heating walls therefor arrangedside-by-side in a row, each of said coking chambersbeing adapted for being chargedfull `of coal save for a gas Space in the crown-space thereof left for collecting gas above the coal charge therein and also being adapted for having a top level for coked 'charges therein; each of said heating walls having main combustion flues extendingnearly up to but terminating below the aforesaid top level for coked chargesand. having separately regulable heating ues alongside the aforesaid gas collecting spaces of the adjoining coking chambers and communicably connected by regulable ports having regulating means therefor with the main heating ues below the separately regulable heating fiues for regulable flow of heating gases from the main heating fiues to the separately regulable heating flues and in which a ported horizontal partition is provided. in the gas collecting space of each of said coking'chambers between the upper and lower levelslfor'such gas collecting space so as to provide a lower gas collecting space and a separate upper cracking chamber within each of said coking chambers in communication with the lower gas collecting space and in the same planevas the separately regulable heating passages in the adjoining heating walls and in which the ported horizontal pal'-,

tition comprises calibrated ports distributed along the length of the partition and provided with dampers and in which an ascension pipe communicates with eachof said cracking chambers at one end thereof.

9. In a coking retort oven, in combination: va series of alternate horizontal coking chambers and heating walls therefor arranged side-by-side in a row, each of said coking chambers being adapted for being charged full of coal save for a gas space `in the crown-space thereof. left for collecting gas above the coal charge therein; eachv of said heating walls having mainv combustion ilues extending nearly up to but terminating'below the aforesaid top level for coked charges and havingseparately regulable heating fiues along-l side the aforesaid gas collecting spaces of the adjoining poking chambers, the main heating fiues being provided with means at their upper parts for off-flow therefrom at their upper parts of waste gasso as to by-pass the separately regulable heating fiues, and the separately regulable heating hues being communicably connected by regulable ports having regulating means therefor with the main heating ues below the separately regulable heating flues for regulable flow of some of the waste heating gases from the main heating flues to the separately regulable heating ues and in which a ported horizontal partition is provided in thev gas collecting spaceof each of said coking chambers between the upper and `lower levels for such gas collecting space so as to provide a lower gascollecting space at a level above the tops of the main heating flues and their waste gas off-flow means but below the bottoms of the separately regulable heating flues, and a separate upper cracking chamber within each of said coking chambers in communication with the lower gas collecting space and in the same plane as the separately regulable heating passages in the adjoining heating walls and in whichl an ascension pipe is communicably connected at one end of the upper cracking chamber of each of said coking chambers and communicable means are provided for connecting the opposite end of the cracking chambers of each of said coking chambers with the end of the cracking chamber of another of said coking chambers opposite its ascension pipe.

i0. In a coking retort oven, in combination: a series of alternate horizontal coking -chambers and heating walls therefor arranged side-by-side in a row, each of said coking chambers being adapted for being charged full o1' coal save for a gas space in the crown-space thereof left for collecting gas above the coal charge therein; each of said heating walls having main combustion flues extending nearly up to but terminating below the aforesaid top level for coked charges and havingseparately regulable heating flues alongsidev the aforesaid gas collecting spaces of the adjoining coking chambers, the main heating ilues being -provided with means at their upper parts for off-flow therefrom at their upper parts of waste gas so as to by-pass the separately regulable heating ues, and the separately regulable heating ues being communicably connected by regulable ports having regulating means therefor with the main heating ues below the separately regulable heating tlues for regulable flow of some of the waste heating gases from the main heating ues to the separately regulable heating fiues `and in which each of said coking chambers is provided with a coking chamber door at one end thereof, each of said doors having at its upper part a leveler door adapted for receiving l a cool leveling bar at varying heights above the tops of the main heating iiues and their waste gas off-flow means for varying the height to whichv the coal charge may be leveled, and each HEINRICH REHscHMmT. 

